27 research outputs found
Horizontal anisotropy and seasonal variation of acoustic fluctuations observed during the 2010–2011 Philippine Sea experiment
The anisotropic ocean environment will lead to variability of ocean acoustic travel time. The variability of travel times comes from several ocean dynamical processes, including eddies, internal tides, and stochastic internal waves. This study analyzes time series of travel time from the Philippine Sea 2010–2011 experiment conducted by the Scripps Institution of Oceanography. In this experiment, a pentagonal array of acoustic transceivers of radius 600-km transmitted 250 Hz pulses for the purpose of observing acoustic variability at multiple time and space scales. Using filtering methods, this study separates variability in travel time in bands associated with eddies, internal tides, and stochastic internal waves. The observed fluctuations in the internal wave band are compared to a simple theoretical model. The result of the research shows that over the year, eddies induce the largest amount of variability. Internal tides and internal waves show comparable fluctuations. There is some seasonal variability. Eddies and internal waves show fluctuations that are fairly isotropic across the array, while internal tides give highly anisotropic fluctuations. This anisotropy is related to the strong directionality of the internal tides that emanate from the Luzon Strait.http://archive.org/details/horizontalnisotr1094547815Lieutenant Commander, Indonesian NavyApproved for public release; distribution is unlimited
Isolasi, Identifikasi, Dan Karakterisasi Bakteri Asam Laktat Dari Dadih Susu Kerbau
Dadih is one of the traditional fermented milk products of West Sumatera. Dadih contain a lot of lactic acid bacteria that acts as a coagulant and preservative. Some lactic acid bacteria also act as a probiotic agent because of characteristics that are resistant to acidic conditions. Some of the main requirements of microbes that can be used as probiotic microbes were resistant to low pH, bile salts, able to colonize, and having antimicrobial activity. Each species of the genus Lactobacillus havedifferent characteristics. This characteristic are influenced by the environment in which the bacteria live. Isolation, identification and characterization of lactic acid bacteria derived from buffalo milk were done. The results of isolated lactic acid bacteria was Lactobacillus plantarum. The characterization of Lactobacillus plantarum indicated that these isolates were able to survive in a concentration of medium containing 0.5% bile salts, resistant to acidic media until pH 2, have antimicrobial activity (inhibit Escherichia coli, Staphylococcus aureus and Enterococcus faecalis)
UJI KEMAMPUAN Lactobacillus casei SEBAGAI AGENSIA PROBIOTIK
Growth Ability of Jatropha Curcas L. Explants on the In Vitro Media Containing IBA and BAProbiotic product is one of the applications of biotechnology that utilize lactic acid bacteria, especially lactobacilli. Some important requirements for microbes that can be used as probiotic include resistance to low pH, ability to grow on bile salts and colonize, and having antimicrobial activity. Each species of the genus Lactobacillus has different characteristics. These characteristics are strongly influenced by the environment in which the bacteria live. This study was carried out in order to characterize Lactobacillus casei which was isolated from dadih. The result of the experiment showed that the isolated L. casei was able to grow on the bile salt at the concentration of 15%, resistant to acid media until pH 2, had antimicrobial activity (significantly inhibited the growth of Escherichia coli, Staphylococcus aureus, and Enterococcus faecalis). The local L. casei isolate has a potential application for use as probiotic microbe.Keywords: Lactobacillus casei, probiotic, lactic acid bacteria, characterization,dadih ABSTRAKProduk probiotik merupakan salah satu aplikasi bioteknologi yang memanfaatkan bakteri asam laktat terutama jenis Lactobacillus. Beberapa syarat utama mikroba yang dapat difungsikan sebagai mikroba probiotik antara lain tahan terhadap pH rendah, mampu tumbuh pada garam empedu, mampu berkoloni, memiliki aktivitas antimikroba. Masing-masing spesies dari Genus Lactobacillus memiliki karakteristik yang berbeda-beda. Karakteristik ini sangat dipengaruhi oleh lingkungan dimana bakteri tersebut hidup. Pada penelitian ini telah dilakukan karakterisasi Lactobacillus casei yang merupakan hasil isolasi dari susu kerbau fermentasi. Dari hasil percobaan menunjukkan bahwa L.casei hasil isolasi mampu hidup sampai dengan konsentrasi garam empedu 15%, tahan terhadap media asam sampai dengan pH 2, memiliki aktivitas antimikroba (positif menghambat Escherichia coli, Staphylococcus aureus, dan Enterococcus faecalis). L. casei yang merupakan isolat lokal memiliki karakteristik yang berpotensi untuk digunakan sebagai mikroba probiotik.Kata kunci: Lactobacillus casei, probiotik, bakteri asam laktat, karakterisasi, dadi
Analysis of the Need for Android Based Mobile Learning Development to Improve Student Science Literations
Science learning in Indonesia has not succeeded in increasing scientific literacy skills, as indicated by the decreasing international ranking from year to year. One of the efforts made to improve scientific literacy is using Android-based learning media. This study aims to analyze the need for the development of instructional media to improve students' scientific literacy at MTs Al Uswah Bergas Semarang Regency. This type of research is a descriptive study that is to describes the current situation. The data instruments used were interviews, observation, and questionnaires. The results of the research on the analysis of the needs for learning media based on android showed that 38% of the 80 students, namely 30 students agreed to develop Android-based learning media, while 29% of the students showed disagreement, 21% strongly agreed, and 12% strongly disagreed. There are aspects of literacy then students including; literacy as mastery of science as knowledge was 63%, 66% as a way of thinking, 62% of scientific literacy as a way of learning, 62% of the aspects of mastery of the competence of the interaction of science, technology, and society. Therefore, it is necessary to conduct research on the development of Android-based mobile learning media to improve students' scientific literac
Development of the 'Curious Scientist' Game to Practice Scientific Thinking Skills
This study aimed to develop an android-based game learning media by applying the steps of the scientific method. Methods: UsingThe development research was adapted the RnD method with the ADDIE model (Analysis, Design, Development, Implementation, and Evaluation). The data collection technique was a validation questionnaire of media experts, linguists, materials, teacher, and student responses. Findings: The validation results of media, language, and material experts were 92.00, 92.00, and 96.00%, respectively, with very feasible criteria. Student response questionnaires in the small and large group trials were 96.00, 94.00, and 89.70%, respectively, with very achievable benchmarks. The teacher's response questionnaire also got more than 80.00%, which was very decent. Conclusion: The result application of the 'Curious Scientist' game learning media is interesting for students. Indirectly, students have learned to use the scientific method approach and apply scientific thinking skills utilizing the learning media game' Curious Scientist.’Penelitian ini bertujuan untuk mengembangkan media pembelajaran game berbasis android dengan menerapkan langkah metode ilmiah . Metode: Menggunakan metode RnD dengan model ADDIE (Analisis, Desain, Pengembangan, Implementasi dan evaluasi). Teknik pengumpulan data melalui angket validasi ahli media, ahli bahasa, materi, respon tanggapan guru, dan respon tanggapan siswa. Temuan: Hasil validasi ahli media, bahasa, materi masing-masing 92%, 92%, dan 96% dengan kriteria sangat layak. Angket tanggapan siswa pada uji coba kelompok kecil dan kelompok besar masing-masing 96%, 94% dan 89.7% dengan kriteria sangat layak. Angket tanggapan guru juga mendapatkan skor lebih dari 80% sehingga mendapatkan kriteria sangat layak. Kesimpulan: Disimpulkan bahwa penerapan media pembelajaran game ‘Curious Scientist’ menarik bagi siswa dan mampu menerapkan metode ilmiah serta berpikir ilmiah
PPM Desa Tungkal I Dalam Pengembangan Produk Berbasis Kelapa Pada Kawasan Lindung Hutan Mangrove
Kabupaten Tanjung Jabung Barat memiliki tanaman kelapa dengan luasan 38.546 Ha dengan produktivitas sebesar 50.494 ton dan produktivitas perhektarnya sebesar 1,2ton/ha (Statistik Perkebunan, 2013 dalam Kemala, 2015). Salah satu sentra penghasil kelapa di Kabupaten Tanjung Jabung Barat adalah di Kecamatan Tungkal Ilir Desa Tungkal I Dusun Bahagia. Di Desa Tungkal I khususnya di Dusun Bahagia. Buah kelapa selama ini hanya diproduksi menjadi kopra dan tempurung dijadikan arang. Sejak tahun 2016, tim pengabdian Fakultas Kehutanan Universitas Jambi telah membina anggota kelompok tani Dusun Bahagia dalam pengelolaan kelapa mulai dari buah kelapa dijadikan Virgin Coconut Oil (VCO), sabut kelapa dijadikan cocopeat dan tempurung kelapa dijadikan briket arang. Tim pengabdian masih melihat ada potensi limbah kelapa yang belum termanfaatkan dengan baik yaitu air kelapa. Air kelapa selama ini hanya dibuang begitu saja tanpa diolah menjadi sesuatu yang bernilai ekonomis. Untuk itu tim pengabdian berinisiatif di 2018 untuk memecahkan masalah mitra tersebut yaitu pengolahan air kelapa menjadi asam cuka dan nata de coco. Dari hasil kegiatan penyuluhan dan demonstrasi pengolahan air kelapa menjadi asam cuka, didapatkan hasil bahwa kelompok tani bakau lestari dan kelompok tani wanita RT.08 Dusun Bahagia Desa Tungkal I sangat antusias terhadap materi pengabdian yang diberikan yaitu pengolahan air kelapa menjadi asam cuka karena selama ini air kelapa di Dusun Bahagia yang melimpah selalu dibuang. Anggota kelompok tani telah memahami dan merasa yakin bahwa mereka dapat mempraktekkan sendiri cara pengolahan air kelapa menjadi asam cuka
Pemanfaatan daun sereh (Cymbopogon citratus) dan lidah mertua (Sansevieria trifasciata) sebagai kisi difraksi sederhana berbantuan tracker
Abstrak. Gelombang cahaya yang mengalami pelenturan ketika melewati sebuah celah sempit disebut dengan fenomena difraksi. Fenomena difraksi dapat dilihat dengan melakukan eksperimen sederhana menggunakan bahan alam. Penelitian ini menggunakan kisi berbahan daun sereh (Cymbopogon citratus) dan tanaman lidah mertua (Sansevieria trifasciata) dengan menggunakan laser merah (λ = 632,8 nm) dengan beberapa variasi jarak kisi terhadap layar. Pola difraksi dianalisis menggunakan perangkat lunak Tracker. Hasil penelitian ini menunjukkan bahwa kisi difraksi menggunakan daun sereh dan lidah mertua menunjukkan fenomena difraksi cahaya sehingga dapat digunakan sebagai kisi difraksi sederhana berbahan alam dengan nilai d=(34.20 +/- 7.86) x 10^-6 m dan d=(62.50 +/- 13.60) x 10^-6 m pada kisi difraksi tanaman lidah mertua. Abstract. The light waves which flex when they pass through a narrow gap are called diffraction. The diffraction phenomenon can be seen by conducting simple experiments using natural materials. This study used a diffraction grating made from lemongrass leaves (Cymbopogon citratus) and sansevieria (Sansevieria trifasciata) using a red laser (λ = 632.8 nm) with several variations in the distance of the diffraction grating to the screen. The diffraction patterns were analyzed using Tracker software. The results of this study show that the diffraction grating using lemongrass leaves and sansevieria show the phenomenon of light diffraction so that it can be used as a simple diffraction grating made from natural ingredients with values d=(34.20 +/- 7.86) x 10^-6 m of lemongrass leaves and d=(62.50 +/- 13.60) x 10^-6 m for the diffraction grating of the sansevieria
Biodiesel Production from Vegetable Oil over Plasma Reactor: Optimization of Biodiesel Yield using Response Surface Methodology
Analisis Kemampuan Berpikir Kritis Siswa Pokok Bahasan Klasifikasi Materi dan Perubahannya
Abstract: This study aims to analyze students' critical thinking skills in science education on the subject matter of classification of material and its changes. This study included quantitative descriptive research. The subjects of this study were the eighth-grade students of MTs Wahid Hasyim Warungasem, Batang with a total of 27 students. The technique of collecting data uses the questions of critical thinking skills which number ten questions. The results showed that critical thinking skills in the basic explanatory aspects were 31% (low category), building basic skills by 61% (medium category), concluded by 17% (very low category), making further explanations of 46% (medium category), and strategy and technique of 20% (very low). Thus, the average critical thinking ability of students as a whole is in the low category with an achievement percentage of 35.2%. Key Words: Analysis of Critical Thinking; Science Education; Material Classificatio
Peningkatan Kemampuan Menulis Artikel Ilmiah Sains Guru Sekolah Dasar melalui Kegiatan Pengabdian Masyarakat
Menulis artikel ilmiah merupakan kegiatan yang sangat penting dalam dunia pendidikan, karena merupakan kegiatan ilmiah yang dapat mengkomunikasikan hasil hasil pemikiran, penelitian dan pengabdian yang dilakukakan oleh sivitas akademika. Tujuan dilakukan pengabdian masyarakat ini adalah meningkatkankemampuan menulis artikel ilmiah dalam bidang sains guru SD se-Kecamatan Gunungpati Semarang. Terdapat 3 kegiatan utama pada pengabdian ini, yaitu pertemuan pertama pelatihan menulis artikel ilmiah sains dengan memberikan contoh dan reviu kritis cara menulis. Kegiatan kedua dengan memberikan penugasan untuk membuat poin inti menulis artikel ilmiah sains, dan kegiatan ketiga melakukan pendampingan untuk memberikan konsultasi artikel ilmiah sains yang akan dibuat. Berdasarkan evaluasi pelaksanaan kegiatan pengabdian dan hasil uji gain ternormalisasi tampak bahwa telah terjadi peningkatan kemampuan menulis artikel ilmiah sains guru SD melalui kegiatan pengabdian masyarakat ini sebesar 0,74 (kategori tinggi). Kesimpulan dari kegiatan pengabdian masyarakat ini adalah terjadi peningkatan kemampuan menulis artikel ilmiah sains guru SD di Kecamatan Gunungpati Semarang